1. Field of the Invention
This invention relates to the structure of a high-temperature regenerator for use in an absorption refrigerator.
2. Background Art
A high-temperature regenerator provided in an absorption refrigerator (including what is called absorption water cooler or heater) takes up the greater part of the entire absorption refrigerator in terms of weight and volume. Therefore, to make compact the absorption refrigerator, it is essential to reduce the size and weight of this high-temperature regenerator. It is also necessary to reduce the discharge of NOx at the time of combustion as an environmental problem in the high-temperature regenerator.
Conventional high-temperature regenerators generally employ a flue and smoke tube system or a flue and liquid tube system. Since it is impossible for the high-temperature regenerators of these systems to eliminate a combustion chamber as a flue, it is difficult to make compact these types of high-temperature regenerators. In other words, the discharge of NOx cannot be reduced when the high-temperature regenerator is made compact, and reductions in the size and weight of the high-temperature regenerator conflict with a reduction in the discharge of NOx.
As what breaks through the limitation of the flue and smoke tube system or the flue and liquid tube system, a flue-less liquid pipe group system in which a plane combustion surface is formed without a combustion chamber has been introduced into a gas fired boiler in recent years. In this flue-less liquid pipe group system, since a combustion flame and combustion gas from a burner such as a plane combustion surface are directly introduced into liquid pipe groups, a combustion chamber is not required, thereby making it possible to make the boiler extremely compact and reduce the discharge of NOx.
However, in the above flue-less liquid pipe group system, a combustion flame and combustion gas from the burner pass in the proximity of the liquid pipe groups. Therefore, the exterior surfaces of the liquid pipes are covered with high-temperature flames and further the heat transfer coefficient of an absorption solution in the pipes is greatly reduced as compared with water, whereby the temperature of the interior wall surface of each pipe is locally increased. As a result, such inconvenience as a corrosion accident or the crystallization of a solution may occur by the local overheating and concentration of an absorption solution caused by a local rise in temperature.